EL lamps are commonly used to illuminate the controls and/or displays of many electronic devices. A typical EL lamp is a capacitive element which illuminates when driven by an alternating current (AC) of proper magnitude and frequency.
A typical EL lamp driver circuit generates a peak-to-peak voltage AC waveform of 100 Volts or more with a frequency of a few hundred Hertz to enable an EL lamp to produce sufficient illumination. Specialized inductor based driver circuitry is often used to generate this AC waveform from a direct current (DC) source, such as a battery. However, inductor based driver circuits can produce relatively large amounts of electromagnetic interference (EMI), which is known to adversely effect the operation of many electronic components.
EL lamps are typically used to illuminate the displays of mobile devices such as wireless telephones, media players, personal digital assistants, and notebook computers. To increase the battery life for a mobile device, it is beneficial to drive its EL lamp application using the least amount of electrical power with relatively low EMI.